Considerations for Electric Utilities to Determine Energy Storage Size for Transmission Deferral to Increase Hosting Capacity

An ageing bulk power system causes increased stress on lines however, upgrading or building a transmission line is a long and arduous process. Recently, non-wire alternatives for transmission deferral have come to the forefront of transmission planning conducted by utilities. This paper presents the application of battery energy storage system (BESS) to mitigate the single branch overload in bulk power system while evaluating the locational impact of the resource. The amount of storage required can vary from system intact to contingency conditions, while also requiring a change in the charge/discharge profile. The Transmission Hosting Capacity (THC) tool developed by Electric Power Research Institute (EPRI) is used to evaluate the size of the BESS required for the purpose. The capability of the THC tool to evaluate BESS size and location is demonstrated using two power systems; IEEE-39 Bus New England System and Synthetic Texas-2000 Bus System. The approach used in the tool as well as the case study results are presented in this paper.